Surface sensitization of internally platinized layered oxide semiconductors K4−xHxNb6O17·nH2O (x ≈ 2.5), H2Ti3O7, and HTiNb05 by RuL32+ (L = 4,4′-dicarboxy-2,2′-bipyridine) yields photocatalysts for the production of H2 and I3− in aqueous iodide solutions. Flash photolysis experiments show that, at pH 3.0, excited-state RuL32+ injects an electron into K4−xHxNb6O17·nH2O and is rapidly re-reduced by I−. Steady-state photolysis at 450 nm in 50 mM aqueous KI (pH 3.0) yields H2 and I3− in stoichiometric amounts, with an initial quantum yield of 0.3%. While H2 and I3−, once formed, do not recombine at an observable rate, the rate of hydrogen evolution decreases as the concentration of 13− increases in the solution.
All Science Journal Classification (ASJC) codes
- Colloid and Surface Chemistry